Improvement in combined steam and vacttum-g-attgre



tno

CHARLESBOURGEOIS, 0l" BUFFALO, NEI/V YORK.

Letters Patent No. 90,988, dated June S, 1869.

IMPROVMENT IN COMBINED STEAM AND VACUUM-GAUGE.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whomt may concern Beit known that I, CHARLES BOURGEOIS, oi' thereference-being had to the accompanying drawings,

making a part of this specification.

rIhe nature of my invention consists in combining within the sameenclosing-case the mechanism of a steam-gauge and the mechanism o1' avacuum-gauge, when so arranged that the index-hand ot' the steamgauge isconcentric with, yet independent of that of the vacuum-guage.A

In the accompanying drawings- Figure I is a front elevation of myimproved gauge, with a portion of the case and index-plate broken away,so as to show the internal mechanism.

Figure II is a cross-sectional elevation ofthe same.. Like lettersdesignatelike parts in cachot' the iigures.

A represents the enclosing-case, the front of which is made open, butcovered by a glassplate, A, held by the screw-rim A2 in a common manner.

' B represents the capsule ofthe steam-gauge. `It is composed of twoelastic metal plates or disks riveted to an interposed ring, so as to.form a steam-tight chamber between them.

To the lower plate is secured a hollow shank, Bl, which passes throughthe side ot' the case A, and has a shoulder, b2, and jam-nut, b3, bywhich it is iirmly secured to the case.

To the outer end of the shank is attached the pipe conducting the steamfrom the boiler into the capsule.

'Thepressure of the steam within the capsule will causeV the elasticplates thereof to swell outward in proportion to the pressure, and it isthis movement of the capsule which is made to operate an index-hand, andindicate, upon a properly-graduated scale, the amount of saidsteam-pressure. v

C represents the pinion-spindle of the steam-gauge located centrallywithin the case, and havingbearings in a frame, D, Dl, and D2, securedto the back side of thefcase by screws, as shown at d3.

E El represent the combined lever and gear-segment by which theexpansion of the capsule is made to actuate the pinion-spindle c. Theasis or shaft ot" this segment has bearings in the frame D D, as shownat e2, contiguous to the upper plate of the capsule, so

that thelever El projects parallel, or nearly so, to the face ofthecapsule, while the gear-segment meshes with the pinion c..

An adjustable bearing-piece, F, is attached to the end of lever E, whichrests in contact with thc capsule, at or near the centre of the same, sothat the movement of the capsule, which takes place underan increase ordiminution in the steam-pressure, will correspondingly move the leverand gear-segment, and therefore. the pinion-spindle c.

An index-hand, G, mounted on the end of pinionspindle c, will indicatethe amount'of movement in the capsuleI upon a proporly-graduatedindex-plate, H, as in common gauges.

A volute-spring, I, applied to the pinion-spindle in a common manner,returns the parts under a contracting movement of the capsule, and astop-screw, Il, prevents thc segun-ut from returning too far.

It is found that equal additions to the steam-pressure do not produce acorresponding increase in the expansion of the capsule, and that,therefore, with an invariable length of lever El, the angular movementsof the index-hand would not be equal for such equal additions, but wouldgrow gradually less as the pressure increased, which would require thedivisions of the index-plate to be graduated to correspond.

It is desirable that the divisions ot' the index-plate should beuniform. To permit this, I make the bearing-piece F with considerablelength in the direction ofthe lever, so that as the pressure increases,and the capsule expands, the working length of lever El will decrease,which will have the effect to increase the movement ot' the segment i'ora given expansion of the capsule, and thereby accomplish the desiredresult.

The capsule J, hollow shank K, lever and gear-segment L L, adjustablebearing-piece M, stop-screw N, and frame D Dl D2 are parts ofthevacuum-gauge, which parts are constructed'and arrangedwith each other ina similar manner to that of the corresponding part-s of the steam-gauge.

P is the index-hand ofthe vacuum-gauge, attached to a sleeve-spindle, Q,surrounding the spindle c, and having for its bearing the stationarysleeve r, secured to the frame Dl.

S is a pinion mounted on the spindle Q, and operated by the segment L,with which it meshes. A volute-spring, I,-is applied to thesleeve-spindle, in such a manner as to cause the pinion S to actuate thesegment as the capsule collapses, and thereby keep the bearing-piece incontact therewith; the operation of this spring being similar to that ofthe spring I, before described.

The dial-plate is provided with two` concentric index-scales t t,properly graduated and numbered, to correspond with the respective handsG P, the one to which the inner scale is adapted being preferably made alittle shorter than the other, for ease of distinction. The hands mayalso be made of different'- color, for the same purpose.

j It is evident that action of the capsule of the vacuumgaugc will bethe opposite ot'v that of the steam-gauge, the vacuum contracting thesides of the capsule of the one, while the steam expands the sides ofthe other in the well-known manner-of such gauges when made separate.

What has been previously stated respecting the unequal expansion of thecapsule of the steam-gauge, and ofthe means employed (the convex surfaceof the bearing-piece) to compensate therefor, will be equally true withrespect to the unequal contraction of the sides ofthe vacuum-capsule,the compensation being effected in a similar manner. l

It will also be perceived that While the two gauges are combined in onecase, so as to form in some respects a single instrument, yet theoperation of each is as perfect, and as' entirely independent of theother as though they were separate and distinct instruments.

By the use of my improvements a great saving is obviously effectedjn thecost of manufacturing such gauges.

-My combined instrument is also more convenient, as a single view of thedial will furnish the required information. as -to the state of bothgauges.

What I claim, and desire to secure by Letters Patent, is-

The combination of the mechanism cfa steam-gauge and the mechanism of avacuum-gauge Within a cylindrical enclosing-case, so arranged as toactuate concentric index-hands over the same dial-plate, substantiallyas herein described.

VitneSSeS: CHARLES BOURGEOIS.

J No. J. BoNNnR, VICTOR H. BECKER.

